The US military is increasing its presence in southeastern Europe and around the Black Sea region, amid heightened tensions with Russia.
With a conflict in Ukraine appearing more likely, Washington wants to assure its NATO allies by increasing its ability to deter and respond to Russia's actions in the short-term and by laying the groundwork for an increased footprint in the region for the future.
It is important for NATO and Russia.
The Eastern Mediterranean Sea and the Black Sea are both located in the region, and both offer access to Russia.
Yugoslavia and Greece were part of the Warsaw Pact during the Cold War.
The region has changed since it joined NATO and the EU. NATO members Albania, North Macedonia, and Montenegro have applied to join the EU.
Russian influence is still considerable. The Western Balkans have strong relationships with the Kremlin because of their cultural, ethnic, and religious ties.
NATO has taken a greater role in the alliance's security architecture by hosting more forces and by supporting NATO movements by land, sea, which is why Moscow recently underscored the importance it places on the region.
There is only one active Aegis Ashore site in Europe. The system is designed to protect European NATO Allies and US deployed forces in the region against the growing threat posed by the proliferation of missiles.
The site in Romania and one under construction in Poland have been criticized by Moscow because they believe the system could be used for offense.
The US military has expanded its presence in the years since the Aegis Ashore site in Romania began operating. The US sent a number of F-16s and relocated 1,000 troops from Germany to reinforce its presence in Romania. NATO troops are temporarily stationed in the country.
The president of Romania has called for a more consistent presence of the US and NATO in the Black Sea region. His calls might now be answered.
NATO Secretary-General Jens Stoltenberg said at the summit on February 16 and 17 that NATO defense ministers agreed to look into establishing battle groups in Romania and other countries in the east, central and southeast of the Alliance.
NATO has four battle groups, totaling 4,500 troops, located in Poland, Latvia, Lithuania, and Estonia. The units were set up in response to Russia.
One of the future battle groups may be hosted by Bulgaria. The Bezmer Air Base is one of the four bases that the US military is present in. Bulgaria has a good relationship with Russia, but it is wary of antagonizing them.
In December, the defense minister of Bulgaria dismissed the idea of NATO troops being sent to the country.
After the NATO summit, he said that Bulgaria would accept a few hundred foreign troops, but that they would only conduct training and exercises.
There are more US troops on their way to Bulgaria. A US Army company stationed in Vilseck, Germany, will travel to Bulgaria in the coming days to train with the military there. A 2006 agreement limits the number of US personnel in Bulgaria.
Albania agreed to host a base for a small number of US special-operation troops. The base will shorten the time it takes American operators to deploy to the region and allow those operators to build ties with their Albanian counterparts, potentially increasing American influence there.
The signs of the US's increasing presence in the region are further south.
The US military frequently trains with its Greek counterpart, but the US has underscored the value of Greece as an ally by signing recent agreements that will give it more access to and presence at Greek facilities.
In October, Washington and Athens renewed and updated their mutual defense and cooperation agreement. US-Greek ties have improved due to worsening relations between the US and Turkey.
The US will be able to deploy troops and equipment to the Black Sea region more quickly if the port of Alexandroupolis becomes a transportation hub.
In October and November, the US performed its two largest disembarkation operations ever in Greece through the port of Alexandroupolis.
The US already has a naval base on the island of Crete, in the heart of the Eastern Mediterranean, and thanks to the updatedMDCA it will be able to expand its presence in mainland Greece.
Greece wants to maintain its working relationship with Russia despite the current tensions, but that may be a difficult balance for Athens to strike as Moscow has already expressed displeasure about the increasing US presence there.
Closer partnerships with Greece and its neighbors have been welcomed by the US.
Defense Secretary Lloyd Austin said after the summit that he had never seen the alliance more relevant and more united, and that it would besure-footed in the face of aggression.
Constantine Atlamazoglou works on security. He obtained a masters degree in security studies and European affairs from the school.